1. Field of the Invention
The present invention generally relates to an apparatus for lifting loads and, more particularly, is concerned with a lift hoist apparatus with endless drive chain and differential drive sprockets.
2. Description of the Prior Art
Disabled and incapacitated persons must often resort to manual assistance in transferring from a bed to a wheelchair and vice versa. Also washing, dressing, and toilet activities by such persons can often require assistance in movement. Many different designs of lifting apparatuses are known in the art for these purposes. Some representative examples of such apparatuses are found in U.S. patents to Spivey (U.S. Pat. No. 3,750,199), Zamotin (U.S. Pat. No. 4,117,561), Kristensson (U.S. Pat. No. 4,236,694), Gettner (U.S. Pat. No. 4,387,473), Hachey et al (U.S. Pat. No. 4,627,119) and Lunau (U.S. Pat. No. 4,805,248).
Suitable lift apparatuses for use in institutions, homes, and hospital settings to assist disabled and incapacitated persons, should be able to perform lifting operations gradually, smoothly and safely so that such persons are not discomforted nor endangered in any way. Preferably, the lift apparatuses should be capable of operation by ordinary persons without special skills nor above average strength. Most current lift apparatuses fall short of reaching these objectives.
Thus, a need still exists for improvement of the design of lift apparatuses for use in different settings to assist movement of disabled and incapacitated persons.